The response of taku and lemon creek glaciers to climate

Abstract

Surface height and mass balance changes of Taku and Lemon Creek Glaciers within Juneau Icefield, Alaska, are examined to determine the relationship between these parameters and climatic forcing. Both Taku and Lemon Creek Glaciers are located in a maritime climate, but they behave very differently. Taku Glacier, a former tidewater glacier, is ∼70 times larger than Lemon Creek Glacier, and its dynamics are largely a result of the post-tidewater glacier cycle which causes insensitivity to climate change during advance phases. Taku Glacier is advancing at present but its surface height, mass balance, and rate of advance have decreased since 1988. Lemon Creek Glacier, a small alpine glacier, is retreating and has maintained a negative mass balance since 1953. Mass balance records from both Taku and Lemon Creek Glaciers correlate well with temperature and show little correlation with precipitation. The mass balance of these glaciers also correlates with the Pacific Decadal Oscillation (PDO). However, the Lemon Creek Glacier mass balance record shows a stronger correlation with the PDO than that of Taku Glacier. Taku Glacier shows a longer delay in response to warming in Southeast Alaska likely due to post-tidewater glacier dynamics, its large accumulation area ratio (AAR), and its size. © 2010 Regents of the University of Colorado.